The 3-Tiered Architecture

The three-tiers refer to the three logical component parts of an application; it splits an application into its three logical component types, Presentation Tier, Business Logic Tier, and Enterprise Information System (EIS) Tier.

Application components can be shared by any number of application systems. The application components, which are developed using the best tool for the job, can be deployed across one or more physical systems.

Benefits from a 3-Tiered Architecture

Three-tiered architectures fully insulate clients from business rules, the underlying data storage, and concurrency issues, resulting in complete encapsulation. Because clients only interact with three-tiered architecture, changes can be made in the database without having to touch a single line of code at the client.

Applications have an open architecture and are fully scalable.

Applications built with three-tiered architecture are also much more maintainable.

The architecture separates responsibility into loosely coupled layers (i.e., user interface, three-tiered architecture, and data storage). Because of this separation of responsibility applications can be modified more easily when the business needs change.

Thin clients that run on the new network computers or on other devices such as mobile phones, or TV boxes, can be more easily implemented. The client needs contain only user interface code.

All business logic and data storage code resides on other machines across the network.

Why a 3-Tiered vs. a 2-Tiered Architecture?

Three-tiered architectures fully insulate clients from business rules, the underlying data storage, and concurrency issues, resulting in complete encapsulation. Because clients only interact with three-tiered architecture, changes can be made in the database without having to touch a single line of code at the client.

Applications have an open architecture and are fully scalable.

Applications built with three-tiered architecture are also much more maintainable.

The architecture separates responsibility into loosely coupled layers (i.e., user interface, three-tiered architecture, and data storage). Because of this separation of responsibility applications can be modified more easily when the business needs change.

Thin clients that run on the new network computers or on other devices such as mobile phones, or TV boxes, can be more easily implemented. The client needs contain only user interface code.

All business logic and data storage code resides on other machines across the network.

Advantages of BBS Architecture

Increase in scalability, performance, and reliability of distributed applications: Server components can be distributed across any number of servers to boost system availability. Rapid modification to these components is possible when business rules or economic conditions dictate. Finally, the location-independence of these components allows system administrators to easily reconfigure system load.
Object reuse: The advantages of a multi-tiered environment extend beyond the life cycle of a single application.
Easier system maintenance: Since application functions are isolated within small granular application objects, application logic can be modified much more easily than ever before.

A more effective use of data and networks:
The application logic is no longer tied directly to the database structures or a particular DBMS. Individual application components work with their own encapsulated data structures which may correspond to a data base structure, or might be a data structure derived from a number of different data sources.

When application objects communicate, they only need to send the data parameters as specified in the abstract interface rather than entire database records, thereby reducing network traffic. The data access objects are the only application components, which interface directly with the databases.

A database could be completely migrated from one DBMS to another without adversely affecting the entire application: only the data access logic would need to be modified. This independence allows IT departments to react better to either business or technological changes.

Technical Features

Imagine being able to use an Internet connection, anywhere in the world, to find a patient in your hospital's BBS system. Using appropriate Firewall setup and password protection, BBS will be as secure as any Internet on-line bank transaction. This ability will be of benefit for remote clinics, private practices and conferences.

BBS assists with rapid production and sharing of operation notes, test or procedure reports and correspondence and has reporting tools built in for non-expert use.

BBS has been given a 3-tiers MS SQL Server database back-end to provide a number of significant features and benefits.

Industrial strength database platform for heavy network use.

Larger multi-user capacity.

Minimized network traffic.

Faster operation over networks, with particular improvement seen over slower networks.